The 1,000 schools with the highest proportion of pupils eligible for free school meals are facing particularly severe funding cuts, according to findings published today.
In secondary schools where more than two fifths of children are on free school meals, the average real-terms loss per pupil between 2015-16 and 2019-20 will be £803 a year, reveals the research by the National Union for Teachers and Child Poverty Action Group.
That amounts to £326 a year more than the average cut per secondary school, the joint research shows.
Among primary schools, those with 40 per cent of pupils on FSM are set to lose £473 per pupil in real terms, per year - £140 more per year than the average.
The NUT and other unions have previously warned that nearly all schools face real-terms cuts under the government's funding settlement for schools and its proposal to introduce a national funding formula from 2018-19.
It has also been shown that the changes will hit schools with the highest number of "just about managing" children - defined as those who have been eligible for free school meals in the past six years.
NUT general secretary Kevin Courtney said: "It is disturbing to find now that the children most in need are in the schools that will be hardest hit. If children who are growing up in poverty do not receive an education that is well resourced and funded then the government will be seriously threatening their life chances."
Alison Garnham, chief executive of Child Poverty Action Group, said: “Poverty at home is the strongest statistical predictor of how well a child will do at school. Schools and teachers can help to weaken that link if they have sufficient resources, but these new findings show that schools in the poorest areas would lose most from the government’s proposed new funding formula.
"That would widen the educational attainment gap and set many of our children up to fail. In the context of the Prime Minister’s social justice agenda, that outcome looks perverse."
The research is based on the Department for Education's forecasts for the impact of the new funding formula on each school, and the National Audit Office’s predictions for cost increases facing schools. The full data for each school can be found at here.
The DfE has pledged to protect per-pupil funding - but only in cash, rather than real, terms. Unions and policy experts say this does not take account of increased costs related to staffing and inflation, or the fact that the £600 million-a-year Education Services Grant is being phased out.
The National Audit Office warned last year that schools need to find £3 billion of funding cuts by 2019-20, equal to an 8 per cent real-terms reduction.
The DfE's consultation on the national funding formula, which is aimed at making school funding fairer and more consistent across the country, closes on 22 March.
A DfE spokesperson said: "Our proposed new funding formula recognises educational disadvantage in its widest sense – including pupils who do not necessarily benefit from the pupil premium but whose families may be only just about managing. It also increases the total funding directed specifically to deprived pupils to £3bn."